How to attach pixelblaze sensor to pixelblaze v3

Hello first time using this product i have the pixelblaze v3 soldered and put together It seems i have one more pin on the pixelblaze than on the pixeblaze sensor header. how do i solder the 2 together or is there another way to attach it.

You just need to solder three of the pins. Connect the Pixelblaze GND, 3v3 and RX pins on the Pixelblaze to the GND, 3.3V and Data pins on the “exp header” side of the sensor board, as shown on the right hand side of this photo. This is described here in the section titled “getting set up”.